Automatic Adjoint Modeling within a Program Generation Framework: A Case Studyfor a Weather Forecasting Grid-Point Model

摘要

A specification-based method for the automatic generation of executable Fortranadjoint code is presented. The method is embedded within the program generation framework for the forward model and automatic differentiation techniques are applied to the forward-model specifications themselves rather than to its Fortran source. The work is discussed in the light of various computational differentiation issues including arithmetic efficiency, forward/ reverse hybridization trade-offs, portability to high-performance platforms, and source-to-source adjoint methodologies. Results of a computer algebra based prototype are illustrated for forward and adjoint code for the dynamics part of a high-resolution limited area weather forecasting grid-point model. (Copyright (c) University of Twente 1995.)